Another family of stochastic Newton methods is based on the so-called Sketch-and-Project framework [1]}, where a low-rank Hessian estimate is used to construct a Newton-like step (with the Moore-Penrose pseudoinverse instead of the matrix inverse). While linear convergence rates have been derived for these methods [2]}, they do not fit into our stochastic oracle framework due to an intrinsic bias arising in these Hessian estimates (see Section REF  for further discussion).
